Functional safety, at varying degrees of integrity and with or without the ISO 26262, has become a cornerstone of SoCs in many key market segments, not just automotive. And the industry goal is to achieve these reliability levels without sacrificing any PPA and while continually reducing TTM. Go figure! I know, that’s like saying, make me an omelet without breaking eggs. And egg substitute is not an option. Jokes aside, in my opinion it is a challenging goal, but definitely not impossible.
One of the key IPs that has a direct impact on the SoC’s safety, security, coherency, bandwidth, latency and hence overall system performance is the interconnect. The interconnect is where all the various requirements melt into one cohesive IP, and the pressure is on to make that next leap and to boldly go where no NoC has gone before. Yep, I am referring to Star Trek. To this day, I am in awe of the futuristic vision which was way ahead of its time, but at the same time gelled with all the other human theatrics and requirements of making a great television series. That’s the kind of ingenuity required to meet the stringent needs of functional safety by integrating the state-of-the-art diagnostic features with the standard but stringent PPA requirements of the interconnect.
Let us start off by briefly reviewing the ISO 26262 requirements and then discuss what next generation interconnect capabilities are required to tackle these.
ISO 26262 requires adherence to two main areas:
While the former requires strict adherence of the company processes to standard practices and regulatory requirements, the latter mandates design safety features and fault protection based on the potential failure modes in order to reach specific ASIL targets. The development process aids in making sure the requirements and feedback are managed with stringent requirements, and in turn provides the user an IP with uncompromised quality and regularly scheduled releases that are rigorously tracked. Though the development process compliance is vital to make sure the IP itself has been built under stringent methodologies to ensure quality and continued support, most companies treat it more as a checkmark to make sure the IP meets those requirements. The analytics is where they spend most of their resources and need most of the assistance in analyzing their SoC/IC, specifically how the interconnect IP fits into their context and analyzing the failure dependencies. This has direct impact on the quality and TTM.
The ISO 26262 process in a nut-shell
The analytics part of ISO 26262 compliance deals with identifying failure modes, analyzing impacts, protecting with safety diagnostic features, and calculating metrics for ASIL targets. From an SoC/IC perspective, it involves analyzing dependencies between various IPs at a system level. This can be a time consuming and resource heavy task, and based on the gap between the achieved and target metrics the SoC/IC designer might have to add more safety features and reanalyze. This can take several iterations, which can be further impacted due to lack of control over a third-party IP’s safety features and its impact on the overall ASIL targets. The goal of a third-party IP provider should be to provide all the design support and collateral to enable the SoC team take control and make appropriate and fast decisions.
Below are some of the key technologies that provide support to users of third-party interconnect IP and alleviate some of the challenges they face in adhering to these requirements.
Achieving the functional safety integrity levels without compromising PPA is an ongoing challenge, especially in the face of shorter TTM. The goal of third-party IPs should be to help its users achieve those targets instead of just providing a coarse level feature set and limited collateral in terms of a Safety Manual. Offering fine grained and configurable protection mechanisms along with a configurable FMEDA that is tailored to the user’s specific needs would go a long way in aiding the users in their path to achieving the required ASIL targets.
Finally, thanks for staying till the end of this journey. In the words of Spock, “Live long and prosper!”
Whether you are a hardware architect looking for cache coherency solutions to realize your ideas into silicon or a SoC designer looking for a high performance and efficient interconnect or a safety manager looking for solutions to build resilient, fault-tolerant systems—NetSpeed has a solution for you.
Crafted @ Lollypop.biz